3166-1 is used for Containers containing international mail, The three letter code is used on machine-readable passports, The two letter code is used by IANA (below) for Internet top level domains, The first two digits of ISO 4217 - Currency Codes e.g. USD for US Dollar. [See: ISO 3166-1 Alpha-2 Code lists]
3166-1 Current codes, 3166-2 - Country subdivision code (e.g. US-CA California), 3166-3 - Code for formerly used names.
See ISO 3166-3 at Wikipedia

People Groups:
People Groups which are distinguished by ethnicity, language, religion, caste and culture are defined in several places. Several Christian organizations have tried to categorize them in order to direct missionary efforts to the unreached. The number of groups ranges from 10,500 to 25,000.
There are over 6,800 languages currently spoken; 2,261 have writing systems. See Christianity Page.

Other Sources:
World Population Prospects Population Database at the United Nations (UN) (esa.un.org/unpp/)
Countries of the World - www.worldhistory.com/timelines/countries.htm population numbers above come from here. (2002 estimates)
World Resources Institute - Regions
Food and Agricultural Organization of the United Nations - Developing, Developed
World Bank - High, Medium, Low IncomeEconomic stats
UNICEF - Industrialized, Developing and Least Developed, Other Regions
United Nations Population Division - Regions, Developing, DevelopedWorld Population Data hereList of Countries at wikipedia.org

1949 Taiwan (English version of Chinese name) was called Formosa ("Beautiful Island" - named in 1517 by the Portuguese) on maps until it was changed to The Republic of China or Nationalist China when Chiang Kaishek and the Nationalist Chinese government were defeated by the Communists and moved from the mainland to Taiwan. Maps around 1950 label it as Nationalist China (Formosa), maps around 1960 just show it as Nationalist China, and starting around 1965 it is shown as Taiwan. ISO Name: TAIWAN, PROVINCE OF CHINA, Government of Taiwan Name: The Republic of China (Taiwan)

1949 French territory Indo-China - Became independent as Cambodia, Laos and Vietnam.

1948 The UN partitions Palestine into a Jewish (Israel) and Arab (Palestine) State, based on a movement started by the British Balfour Declaration in 1917. The League of Nations ratified the declaration and in 1922 appointed Britain to rule in Palestine. Egypt, Syria, Jordan, Iraq, Lebanon attack Israel in 1948. Israel defeats them and controlls about half the land the UN intended for the new Arab state.

1947 India won independence from British rule and was divided into India (mainly Hindu) and Pakistan (East & West) (Muslim), Kashmir, a region between India and West Pakistan could not decide which country they wanted to join. The border has been disputed ever since.

1938 Siam renamed Thailand.

1926 Saudi state renamed Saudi Arabia. It became independent of Britiain in 1927.

1922 Ireland (Southern part) becomes independent of United Kingdom of Great Britain.

1918 Soviet Union or USSR (Soyuz Sovetskikh Sotsialisticheskikh Respublik, SSSR written in the Cyrillic alphabet as CCCP) formed after the Bolshevik Revolution. It was the successor state of the Russian Empire but was smaller as a result of the independence of Poland, Finland and the Baltic States.